Wednesday, November 12, 2014

She looked at me gravely. “Without me pointing at the same things as you do, without this intersubjectivity, how could there be any referential meaning?” she said. “You would not know that this situation is reality, if not for another, independent person to confirm it.”

I looked into her alert baby eyes and suddenly realized that my 14month old daughter is unlikely to express this stupid argument so eloquently. Argh, one of these dreams again! But I love the way my impertinent referentialist daughter lost the argument against her anti-realist dad.
As I awake from a dream turned lucid, I feel both exhilarated and the pang of melancholy of not yet being able to have that conversation with her nascent mind.

True Computation is only possible in a silicon substrate. Brains cannot compute. It might look as if a brain could compute, but brains can only simulate computation. Obviously, nature is not able to imitate the computation feats of a silicon processor, but just as a thought experiment, some philosophers have suggested that a brain could take in the same inputs as a silicon chip, and return the same results. But that would not be True Computation. Just as a simulated thunderstorm cannot make you wet, and simulated money cannot make you rich, simulated computation lacks an essential element that can only be supplied by the intrinsic powers of silicon transistors.

Thursday, October 16, 2014

If you should happen to be interested in how to turn an abstracted version of basic electronic circuitry into a puzzle game, read on.

My favorite casual computer games are puzzles that allow me to pore over the solutions for hours. I want lots of little things to go whirr! and click! and then do my bidding. If you have not played Trainyard yet, I strongly recommend checking it out! (You can start with the free edition, Trainyard Express, which thankfully does not have any advertising or in app purchases, by the way.) Trainyard lets you draw tracks with your finger, and little locomotives are traversing them in funky patterns, changing their colors on the way, before either crashing or finding their destinations.

Trainyard is in principle Turing complete (i.e. you could build a computer in it), but Trainyard's playing area is limited to 7x7 fields, and you cannot place any of the interesting stuff yourself (like replicators and color changers), so practically, that's not possible.

On the other end of the spectrum, there is Minecraft, the famous open-ended, almost infinitely large brick-laying playground. Among other things, Minecraft is a three-dimensional cellular automaton, with a playing field that is 30 million cells wide and deep, and 255 cells high. Cells may interact with each other up to a distance of 15, with most of the interaction limited to the directly adjacent cells. Using specific materials that act as conductors, isolators, switches and repeaters, players can wire up their virtual fortresses with button-operated trap-doors and lighting. And some relentless players have figured out how to build computers in the game.

Tuesday, September 23, 2014

Exploring consciousness through anti-representationalism. No, we are not connected to a world of things through our bodies. Our connection is much more fragile: a gossamer network (of nerves, says the best theory we have) that admits a few bits of information at a time is all we have to make do with. Meaning is what we construct in our minds, not what we find in the world.

Friday, September 19, 2014

The parts of our brains that are responsible for the majority of our decisions tie into our most basic desires and impulses predate our history as primates, or even mammals. You may be familiar with the idea of the "triune brain" (McLean 1990), which suggests that we inherit physiological and territorial drives from reptiles, social behavior (along with the limbic system, that implements it) from early mammals, and cognitive strategies from higher mammals. Such a strict division is too simplistic, of course, but makes for a beautiful metaphor.

Indeed, I believe that we are controlled by three classes of drives: physiological ones (hunger, thirst, pain avoidance, libido etc.), social ones (affiliation, internal legitimacy, romantic affection), and cognitive drives (competence, uncertainty reduction, and aesthetics). All goal-directed behavior is directed upon the satisfaction of one (sometimes more) of these drives, or the avoidance of their frustration. Satisfying a drive creates pleasure, frustration a displeasure signal, and these are responsible for learning.
This happens mostly intuitively: the decision function is implemented outside the consciously accessible parts of our minds. It evaluates the relative strength of the urges, combines them with the expectancy of fulfilling them, adds a bonus threshold on the currently active motive, and there we go.

Wednesday, August 13, 2014

So you are here for this session of Yogilates. Some of you I have seen here before, some are new to this. You may find that the exercises become easier with time, but this will subside, of course, as your body is inevitably wearing out as the years pass.
Please lie down on your back and try to find a somewhat comfortable or at least bearable position. Inhale, stretch your legs and your arms, exhale, pull up your knees to your chest, and wrap your hands around your shins.
Rock slowly from side to side while imagining that this fetal pose offers protection and consolation. Inhale and stretch out again, then exhale and sit up, cross your legs and come forward onto all fours, if you can still manage to do it this way. Inhale while letting your belly drop, exhale while rounding your back. Hold the pose. Keep holding it. Hold on, and feel how the lack of breath compresses your stomach into a hard lump of anxiety.
Inhale again, while curling your toes into the ground, straightening your legs and lowering your head. Get down on your legs while keeping your arms on the ground. Repeat this cycle four times at your own speed. Don't forget your breathing. Now sense the futility of movement as you repeat this cycle four more times.
Stretch, exhale, fold, hold the tension. Now get on your knees, raise your arms and head toward the sky, inhale while keeping your arms stretched out and letting them drop slightly to your sides. The opening motion might give you an illusion of connectedness, but you are all alone.

(spoken in the grave voice of Portia Brockway, who is an excellent instructor, by the way)

Thursday, July 3, 2014

Chris Lee just wrote a nice introduction regarding the disenchantment of physicists with realist notions. Rather than re-explaining the experiments (see Bell's theorem, for starters), let me just point out what I consider to be the most important consequence for our cosmology, namely: the world is not a physics engine.

(Physics engine: computing the interaction of things located in time and space)

Obviously, it is impossible to know the nature of the world we inhabit while being entirely caught up inside it: the basic trouble with epistemology is that the world only shows us phenomena (Husserl), or, more basically but inaccurately: discernible differences, i.e. information, and not its structure itself. Thus, we cannot know if anything beyond the phenomena or the information exists. And if it does, what do we mean by "existence"?

Sunday, June 22, 2014

Without some form of deception, society would be completely impossible. Lies of omission allow us to cooperate.

This prompted Joi Ito's elaboration: we tend to make communicative statements (including non-verbal ones, like the choice of clothing) in a very particular context. How can we make a communicative statement work when the context breaks down? In fact, this breakdown of context is almost the norm for communication that is available to non-homogenous audiences, say, both your peers and your parents, following you on Facebook: the same statement may very well mean very different things different recipients. By careful omission, which amounts to a type of deception, we may be able to realize our communicative intent even if the signs and concepts that make up our message mean different things to individual recipients.

This insight has interesting implications: First of all, there are several distinct kinds/modes of public communication. One is concerned with the transmission of content (ideas, arguments, data etc.). The other one is concerned with the elicitation of social behavior: we want the recipients of the communication to interact in certain ways, adopt a position towards us in relation to their own, and so on.

Tuesday, February 25, 2014

Julia is a rather new programming language; it started out in 2009 and is being developed by bunch of scientific programmers at the MIT. The syntax looks a little like Matlab, and the authors really seem to have mathematical and statistical applications in mind. But in my view, Julia has the potential to become really popular in a few short years down the road. Julia's syntax is almost as pleasant to me as Python's, nothing looks too arcane and mind-bending, and yet at its core, it is a much more modern language.